JP2007334922A - Recording power adjusting method, and optical recording and reproducing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recording power adjusting method capable of highly precisely setting the optimum recording power, and to provide an optical recording and reproducing device. <P>SOLUTION: A trial writing is performed using a plurality of kinds of recording power Pwm, modulation degree Mm corresponding to each recording power Pwm are calculated. An evaluation value Smn=Mnm(Pwm-Pcn) is calculated using a plurality of kinds of recording power correction item Pcn, Pcn when correction recording power (Pwm-Pcn) and an evaluation value Smn are close most to a straight line state is decided as the optimum recording power correction item Pc0. Correction recording power Pth0 in which modulation degree becomes 0, that is, the evaluation value Sm becomes 0 when a relation property of correction recording power (Pwm-Pco) and the evaluation value Sm in Pc0 is assumed to an approximate straight line is obtained. A recording power threshold value Pth=Pth0+Pc0 is calculated using Pth0 and the optimum recording power correction item Pc0, and Optimum recording power Popt is obtained by performing the prescribed operation for Pth. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a recording power adjustment method and an optical recording / reproducing apparatus, and more particularly to a method for adjusting recording power based on a relational characteristic between recording power and modulation degree, and a relational characteristic between recording power and modulation degree. The present invention relates to an optical recording / reproducing apparatus having means for adjusting recording power.

  At present, CDs (compact discs), DVDs (digital versatile discs), etc. have been commercialized and spread as optical discs (information recording media), and in recent years the capacity has been increased as next-generation optical discs. Realized BD (Blu-ray Disc) has begun to be commercialized. The BD includes a BD-ROM (ROM, ROM type optical disc) for reproduction only, a BD-RE (rewritable, RW type optical disc) that is rewritable, a BD-R (recordable, R type optical disc) that is write once, and the like. There are various types. Among these, the recordable discs (BD-RE and BD-R discs) have different optimum recording powers for recording for each disc type and for each manufacturer. Therefore, the drive device (optical recording / reproducing device) needs to set an optimum recording power according to each optical disc. However, since there is a variation in output recording power among the drive devices, the set recording power varies. As a result, good recording may not be performed. Accordingly, each drive device has a configuration in which trial writing is performed in a predetermined area on each optical disc, and the optimum recording power is adjusted according to each optical disc.

  Among these optical discs, BD-RE and BD-R use a recording power adjustment method (kappa method) using designated recording power Ptarget, designated modulation degree Mind, parameters κ, and ρ specific to each medium. It is described in the standard. Such a recording power adjustment method using the κ method is characterized by the relationship between the recording power obtained by trial writing and the modulation degree obtained from the reproduction signal amplitude of the signal, and the Ptarget, Mind, κ, And the optimum recording power is adjusted based on the ρ value.

  Further, in the BD-RE and BD-R standards, it is recommended to use the linear fit method among the κ methods. In this linear fitting method, first of all, the specified modulation degree Mind in the optical disc among the relational characteristics of a plurality of types of recording power Pwm set at the time of trial writing and the reproduction signal amplitude of the signal recorded by each Pwm and the modulation degree Mm. The evaluation value Sm = MmxPwm is obtained in the range near the designated recording power Ptarget and the designated modulation degree Mind, and the recording power threshold Pth at which the modulation degree becomes zero when the relational characteristic of Pwm and Sm is linearly approximated in this range. The optimum recording power Popt is obtained by calculating Popt = κxρxPth from the Pth and the parameters κ and ρ of the optical disc.

  By the above optimum recording power adjustment by the κ method, it is possible to suppress variations in output recording power among the drive devices.

  However, the reason why the set recording power varies is not limited to the output recording power variation between the drive devices.

  Depending on the optical disc, the relationship between the recording power Pwm and the evaluation value MmxPwm is not linear even in an area near the designated recording power Ptarget, and the optimum recording power may not be determined with high accuracy.

  FIG. 9 of Patent Document 1 shows the characteristic relationship between the recording power Pwm and the evaluation value MmxPwm in an optical disc that can accurately determine the optimum recording power Popt by the conventional κ method. In such an optical disc, the characteristic relationship between Pwm and MmxPwm is linear, and therefore when the linear approximation is performed in the vicinity of the designated recording power Ptarget corresponding to the designated modulation degree Mind read from the optical disc, the modulation degree M is zero. That is, the recording power threshold value Pth at which the evaluation value MmxPwm is zero is always obtained uniquely. Therefore, the optimum recording power Popt calculated using the obtained Pth is also uniquely determined.

On the other hand, FIG. 1 shows a relational characteristic between Pwm and MmxPwm in an optical disc in which an accurate optimum recording power Popt cannot be determined by the conventional κ method. In the characteristic relationship of FIG. 1, when linear approximation is performed in the vicinity of the designated recording power Ptarget corresponding to the designated modulation degree Mind, the slope of the approximate line and the Pw intercept (= Pth) vary depending on the range in which the linear approximation is performed. FIG. 2 shows an example of the variation of the recording power threshold Pth determined when the recording power adjustment is executed 100 times using the conventional κ method in such an optical disc, by the change amount and the frequency with respect to the average value of Pth. FIG. As shown in FIG. 2, the recording power threshold value Pth varies greatly because the range for performing linear approximation changes in each recording power adjustment. As a result, the optimum recording power Popt calculated using Pth having these variations also varies greatly. Therefore, it is difficult to accurately determine the optimum recording power for an optical disc in which the relationship between Pwm and MmxPwm is not linear.

  Further, in the optical disc having the relational characteristics of Pwm and MmxPwm shown in FIG. 1 and FIG. 9 of Patent Document 1, for example, in a dual-layer optical disc, layers other than the target layer are in an unrecorded state or in a recorded state. As a result, it has been found that the degree of modulation varies greatly as the amount of reflected light changes.

  FIG. 3 schematically shows the fluctuation of the modulation degree. Since the modulation degree M is given by M = (Henv−Lenv) / Henv using the upper envelope level (Henv) and lower envelope level (Lenv) of the reproduction signal, the state (a) shown in FIG. When changing to b), since the maximum value Henv changes even though (Henv-Lenv) does not change, the modulation degree M changes.

FIG. 4 shows the relational characteristics of Pwm and Mm in the state (a) and the state (b) when the above problem occurs for the optical disk having the relational characteristics of FIG. Further, FIG. 5 shows the relational characteristics of Pwm and PwmxMm in the states (a) and (b), and the optimum recording powers obtained therefrom. As shown in FIG. 4, the designated recording power corresponding to the designated modulation degree Mind.
Ptarget has a different value in each of the states (a) and (b). Therefore, as shown in FIG. 5, in the states (a) and (b), linear approximation is performed in different ranges, and the recording power Pth obtained in each state has a different value. FIG. 6 shows an example of the variation and the frequency of the recording power threshold value Pth determined when the recording power adjustment is executed 100 times using the conventional κ method in the states (a) and (b) of the optical disc. FIG. The difference between the states (a) and (b) is due to a change in the amount of reflected light from layers other than the target layer, and the optimum recording power Popt, that is, the recording power threshold value Pth should be essentially the same in each state. Actually, as shown in FIG. 6, the recording power threshold value Pth differs greatly between the states (a) and (b). Therefore, when the modulation degree fluctuation shown in FIG. 3 occurs, it is difficult to accurately adjust the optimum recording power with the conventional κ method.

  The present invention is a method by which the optimum recording power Popt can be accurately determined even for an optical disc having the above problems.

JP 2002-298357 A JP-A-2005-149538

  In order to solve the above problems, in the present invention, a predetermined signal is recorded using a plurality of types of recording power Pwm (m is an integer), and a modulation degree Mm corresponding to each recording power Pwm from a reproduced signal of the recorded signal. And an evaluation value Smn = Mmx (Pwm−Pcn) is calculated using a plurality of types of recording power correction terms Pcn, and an optimum recording power correction term is calculated from the relationship between the corrected recording power (Pwm−Pcn) and the evaluation value Smn. Pc0 is determined, and a corrected recording power Pth0 is calculated and obtained when the degree of modulation is zero, that is, the evaluation value Sm0 is zero, when the relationship characteristic between (Pwm−Pc0) and Sm0 using the determined Pc0 is linearly approximated. The recording power threshold value Pth = Pth0 + Pc0 is calculated using Pth0 and Pc0, and the optimum recording power Popt is determined by performing a predetermined calculation on the obtained Pth. .

Details of the recording power adjustment method of the present invention will be described below.
Here, description will be made using an optical disc as an information recording medium. The information recording medium is not limited to an optical disc as long as it is an information recording medium that performs recording by irradiating light.

  A signal of a predetermined pattern is recorded in a predetermined area of the optical disc using a plurality of types of recording power Pwm. By reproducing the signal recorded at each Pwm, the reproduction signal amplitude Henv and Lenv are measured, and by calculating Mm = (Henv−Lenv) / Henv, the modulation degree Mm corresponding to each Pwm is obtained. An evaluation value Smn = Mmx (Pwm−Pcn) is calculated using a plurality of types of recording power correction terms Pcn (n is an integer), the recording power Pwm, and the modulation degree Mm. The relationship characteristics between the corrected recording power (Pwm−Pcn) and the evaluation value Smn at each Pcn are compared, and Pcn whose relationship characteristics between (Pwm−Pcn) and Smn are closest to a straight line is determined as the optimum recording power correction term Pc0. . A linear approximation is performed on the relational characteristic between (Pwm−Pc0) and Sm0 in the determined Pc0 to obtain a corrected recording power Pth0 at which the modulation degree is zero, that is, the evaluation value Sm0 is zero. The recording power threshold value Pth is obtained by calculating Pth = Pth0 + Pc0 using the obtained Pth0 and the Pc0. The optimum recording power Popt is determined by multiplying the obtained Pth by a predetermined calculation, for example, the ratio α of Popt / Pth set for each optical disk, and recording on the optical disk is performed using the determined Popt.

  FIG. 7 shows the variation of the recording power threshold Pth determined when the recording power is performed 100 times on the same optical disk as in FIG. It shows with. Further, FIG. 8 shows the variation and frequency of the recording power threshold value Pth determined when the recording power adjustment is performed 100 times using the above method on the optical disk having the same modulation degree variation as FIG. Show. As shown in FIGS. 7 and 8, by using the present invention, the variation of the recording power threshold value Pth becomes very small, and furthermore, an appropriate Pth can always be determined for the modulation degree variation.

  According to the present invention, optimum recording power adjustment is possible even in an optical disc in which the relational characteristic between the recording power Pw and the evaluation value MxPw deviates from a straight line and an optical disc in which the modulation factor M fluctuates, as compared with the conventional recording power adjustment method (κ method). Can be performed with high accuracy.

Hereinafter, a recording power adjusting method as an embodiment of the present invention will be described with reference to the drawings.
First, in this embodiment, an optical disk is used as an information recording medium, an optical disk device is used as an information recording / reproducing apparatus, and the configuration thereof is described. Then, recording power adjustment as an embodiment of the optical disk apparatus which is an information recording / reproducing apparatus is performed. A method will be described.

FIG. 9 shows a block diagram of a main configuration of an optical disc apparatus used in the embodiment of the present invention.
The optical disk 10 is CLV (Constant Linear Velocity) controlled or CAV (Constant Angle Velocity) controlled by the spindle motor 12. An optical pickup unit 14 is provided opposite to the optical disc 10, and a signal is recorded on the optical disc 10 by emitting a laser beam 16 having a recording power from a laser diode (LD), and a laser beam having a reproducing power is emitted from the LD. Read the recorded signal. Further, when the optical disc 10 is a rewritable optical disc, a laser beam having an erasing power (reproducing power <erasing power <recording power) is emitted from the LD to erase the recorded signal. The recorded signal is generated by irreversibly changing the material of the recording film of the optical disc 10 with a laser beam of recording power, and by changing the recording film in a crystalline state to an amorphous state by heating and quenching. May be recorded. In this embodiment, any recording method can be used. In the latter case, erasing is performed by irradiating erasing power to return the amorphous state to the crystalline state.

When recording a signal, the recording signal is encoded by the encoder 18 and supplied to the LD drive unit 20. The LD driving unit 20 generates a driving signal based on the encoded recording signal, and supplies the driving signal to the LD in the optical pickup unit 14 to record the signal. The recording power value in the LD driving unit 20 is determined by a control signal from the control unit 22. Prior to recording the signal, the control unit 22 performs test writing using a plurality of types of recording power in the test writing area of the optical disc 10, and determines the optimum recording power based on the signal quality of the test writing.

  On the other hand, at the time of data reproduction, the RF signal output from the optical pickup unit 14 is supplied to the RF signal processing unit 24. The RF signal processing unit 24 includes an RF amplifier, an equalizer, a binarization unit, a PLL unit, and the like, processes the RF signal with these, and supplies the processed signal to the decoder 26. The decoder 26 decodes the signal based on the binarized RF signal and the synchronous clock reproduced by the PLL unit and outputs it as reproduced data. The Henv / Lenv acquisition unit 28 amplifies the reproduction signal output from the optical pickup unit 14, calculates the upper envelope level (Henv) and the lower envelope level (Lenv) of the reproduction signal, and uses the control unit 22 for signal quality evaluation. To supply. Further, the reproduction RF signal from the RF signal processing unit 24 which is an RF signal acquisition system is also amplified and supplied to the control unit 22 for signal quality evaluation. In addition, at the time of data recording / reproduction, a circuit for generating a tracking error signal and a focus error signal to control the focus servo and tracking servo, and a wobble signal formed on the optical disk 10 are reproduced to perform address demodulation or rotational speed control. Some circuits are used, but since these are the same as those in the prior art, description thereof is omitted.

  The control unit 22 determines the optimum recording power based on the reproduction signal quality of the trial writing from the RF signal processing unit or the Henv / Lenv acquisition unit. That is, the control unit 22 calculates the modulation degree M based on the signal from the RF signal processing unit, or the Henv / Lenv acquisition unit, and the modulation degree in the relational characteristic of the modulation degree Mm corresponding to a plurality of types of recording power Pwm. The optimum recording power Popt is determined based on the recording power threshold value Pth at which becomes zero, and is supplied to the LD driving unit 20.

FIG. 10 shows a configuration block diagram of the control unit 22 in FIG.
Specifically, the control unit 22 is configured by a microcomputer, and the functional block includes a modulation degree calculation unit, an optimum recording power adjustment unit / determination unit, a storage unit, and a parameter storage unit. Specifically, the modulation degree calculation unit, the optimum recording power adjustment unit, and the determination unit can be configured by a single CPU, and the storage unit and the parameter storage unit can be configured by RAM.

  The control unit 22 is supplied with a signal from the RF signal processing unit or the Henv / Lenv acquisition unit via an interface (not shown), and is input to the modulation degree calculation unit. The modulation degree calculation unit calculates the modulation degree M from the supplied signal. The calculated modulation degree Mm is stored in the storage unit in association with each recording power Pwm in the optimum recording power adjustment. The optimum recording power determination unit determines a recording power threshold value Pth at which the modulation degree becomes zero based on the stored relationship characteristics between the recording power Pwm and the modulation degree Mm, and performs a predetermined calculation using the recording power threshold value Pth. By doing so, the optimum recording power Popt is determined.

Hereinafter, the recording power determination method will be described in more detail with reference to flowcharts.
FIG. 11 shows a process flowchart of the control unit 22 in the present embodiment.

  First, the control unit 22 sets a plurality of types of recording power Pwm according to a predetermined condition, for example, reads out the average optimum recording power in the disc stored in advance in the optical recording / reproducing apparatus, or in the information control area of the optical disc in advance. The recorded average optimum recording power is reproduced and read out, and set based on the average optimum recording power, for example, a plurality of types of recording power setting values Am (m is an integer, stored in advance in the optical recording / reproducing apparatus) For example, m = 1, 2, 3,... 16) is read out, and each type of Am is used to set a plurality of types of recording power Pwm by the formula Pwm = (average optimum recording power) xAm, and each Pwm is used as a test writing area of the optical disc. Then, a predetermined signal pattern is recorded, for example, an isolated 8T mark having a predetermined length is recorded (S101).

  By reproducing the test-written area, the Henv and Lenv of the reproduction signal corresponding to each Pwm are measured, and the modulation degree Mm defined by the equation Mm = (Henv−Lenv) / Henv is calculated (S102). ). An example of the relationship between the modulation degree Mm and the corresponding recording power Pwm is shown in FIG.

  Next, a plurality of types of recording power correction terms Pcn are set according to predetermined conditions. For example, the average optimum recording power in the disc stored in the optical recording / reproducing apparatus in advance is read out, or the average optimum recording power recorded in the information control area of the optical disc in advance is reproduced and read out, and the average optimum recording power is read out. Can be set based on Alternatively, for example, a plurality of types of recording power correction term setting values Cn (n is an integer, for example, n = 1, 2, 3,..., 16) stored in advance in the optical recording / reproducing apparatus are read, and each Pn is used to calculate the expression Pcn. = (Average optimum recording power) xCn can be used to set a plurality of types of recording power Pcn (S103).

  An evaluation value Smn = Mmx (Pwm−Pcn) is calculated for each recording power correction term Pcn, and the recording power correction term Pcn when the relational characteristic between the corrected recording power (Pwm−Pcn) and the evaluation value Smn is most linear. Is determined as the optimum recording power correction term Pc0. For example, in order from n = 1, the relational characteristic of (Pwm−Pcn) and Smn in Pcn is linearly approximated to calculate the sum Ln of the square errors, and Pcn where the sum Ln of the square errors has the minimum value is Pc0. Determine (S104). FIG. 13 shows an example of the result of determining the recording power correction term Pc0 according to the above example. As Pcn approaches Pc0, the relational characteristic of (Pwm−Pcn) and Smn approaches a linear shape.

  Next, as shown in FIG. 14, a linear approximation is performed on the relationship between the corrected recording power (Pwm−Pc0) and the evaluation value Sm0 in the determined optimum recording power correction term Pc0, and the modulation degree is zero, that is, the evaluation value is zero. The corrected recording power Pth0 is calculated, and the recording power threshold value Pth is calculated by the expression Pth = Pth0 + Pc0 using the corrected recording power Pth0 and the optimum recording power correction term Pc0 (S105).

  A predetermined calculation is performed on the calculated recording power threshold value Pth, for example, the ratio Popt / Pth = α between the optimum recording power Popt and the recording power threshold value Pth in the disc stored in advance in the optical recording / reproducing apparatus is read, or the optical disc The optimum recording power Popt is calculated by reproducing and reading the ratio Popt / Pth = α between the optimum recording power Popt and the recording power threshold value Pth on the disc recorded in the control information area, and calculating the formula Popt = αxPth. (S106).

  Α (Popt / Pth), which is the ratio between the optimum recording power Popt and the recording power threshold value Pth of the optical disk used here, is a value specific to an information recording medium such as an optical disk, and is determined for each type of optical disk, for example. It is. The α may be recorded in advance on the disk when the disk is manufactured, for example, when a substrate is manufactured. For example, in the case of BD, the κ value, which is a value unique to the disc, is stored in the wobble together with the address information at the time of disc manufacture, so this α may be recorded on the disc as well. . If this α is not recorded in the information possessed by the disc, α may be calculated from the related information, and considering that α is a value determined for each type of optical disc, If the value of α corresponding to a possible (possible) type of optical disk is predicted and the optical recording / reproducing apparatus has the data, the optical reproducing apparatus depends on the type of optical disk that needs to be irradiated with light. α may be determined.

  Recording on the recording disk is performed using the optimum recording power Popt determined by the control unit 22 as described above.

  In the first embodiment, the setting of the plurality of types of recording power Pwm based on the average optimum recording power in (S101) is not limited to the above method, and the recording power in the disc stored in the optical recording / reproducing apparatus in advance. Read the swing width ΔP, or reproduce and read the recording power swing width ΔP previously recorded on the optical disc, and use the average optimum recording power on the disc to calculate the equation Pwm = (average optimum recording power) −mxΔP (m is It may be set by an integer, for example, m = 16). Even when set in this way, the same effect as in the first embodiment can be obtained.

  In the first embodiment, the setting of the plurality of types of recording power Pwm in (S101) is not limited to the above method, and the recording power Pwm setting center value in the disc stored in advance in the optical recording / reproducing apparatus is read, or The recording power Pwm setting center value recorded in advance in the information control area of the optical disc is reproduced and read, and set based on the recording power Pwm setting center value, for example, the information stored in the optical recording / reproducing apparatus in advance. The recording power setting value Bm (m is an integer, for example, m = 1, 2, 3... 16) on the disc is read, or the recording power setting value Bm previously recorded in the information control area of the optical disc is reproduced and read. Even if each Bm is used and set by the formula Pwm = (recording power Pwm setting center value) × Bm There. Even when set in this way, the same effect as in the first embodiment can be obtained.

  In the third embodiment, the setting of the plurality of types of recording power Pwm based on the recording power Pwm setting center value in (S101) is not limited to the above method, but in the disc stored in advance in the optical recording / reproducing apparatus. The recording power amplitude ΔP is read, or the recording power amplitude ΔP previously recorded on the optical disc is reproduced and read, and the formula Pwm = (recording power Pwm setting center value) is used by using the recording power Pwm setting center value on the disc. ) ± mxΔP (m is an integer, for example, m = 0 to 8). Even when set in this way, the same effect as in the first embodiment can be obtained.

  In the first embodiment, the setting of the plurality of types of recording power Pwm in (S101) is not limited to the above method, and the range in which the plurality of types of recording power Pwm in the disc stored in advance in the optical recording / reproducing apparatus is set. Or read and read a range in which a plurality of types of recording power Pwm recorded in advance in the control information area of the optical disc is set, and the optical recording / reproducing apparatus arbitrarily sets a plurality of types of recording power within the range. May be. Even when set in this way, the same effect as in the first embodiment can be obtained.

  In the first embodiment, the predetermined signal pattern to be recorded using each recording power Pwm in (S101) is not limited to the above-described method, and the same signal pattern may be used for all the recording powers. Even when set in this way, the same effect as in the first embodiment can be obtained.

  In the first embodiment, the setting of the plurality of types of recording power correction terms Pcn based on the average optimum recording power in (S103) is not limited to the above method, but in the disc stored in advance in the optical recording / reproducing apparatus. The ratio I between the recording power correction term setting center value and the average optimum recording power and the recording power amplitude ΔP are read out, or the ratio I between the recording power correction term setting center value and the average optimum recording power that has been previously recorded on the optical disc and the recording The power amplitude ΔP may be reproduced and read, and set by the formula Pcn = (average optimum recording power) × I ± nxΔP (n is an integer, for example, n = 0 to 8) using the average optimum recording power on the disc. . Even when set in this way, the same effect as in the first embodiment can be obtained.

In the first embodiment, the setting of the plurality of types of recording power correction terms Pcn in (S103) is not limited to the above method, but the recording power correction term Pcn setting center in the disc stored in advance in the optical recording / reproducing apparatus. A value is read out, or a recording power correction term Pcn setting center value recorded in advance in the information control area of the optical disc is reproduced and read out, and set based on the recording power correction term Pcn setting center value. The recording power setting value Dn (n is an integer, for example, n = 1, 2, 3,... 16) stored in the recording / reproducing apparatus is read or recorded in advance in the information control area of the optical disk. The set value Dn is reproduced and read out, and the expression Pcn = (recording power correction term Pcn is being set) using each Dn. It may be set by (heart value) xDn. Even when set in this way, the same effect as in the first embodiment can be obtained.

  In the eighth embodiment, the setting of a plurality of types of recording power correction terms Pcn based on the recording power correction term Pcn setting center value in (S103) is not limited to the above method, but is previously stored in the optical recording / reproducing apparatus. The recording power amplitude ΔP on a certain disk is read or the recording power amplitude ΔP previously recorded on the optical disk is reproduced and read, and the expression Pcn = ( Recording power correction term Pcn setting center value) ± nxΔP (n is an integer, for example, n = 0 to 8). Even when set in this way, the same effect as in the first embodiment can be obtained.

  In the first embodiment, the setting of the plurality of types of recording power correction terms Pcn in (S103) is not limited to the above method, and the plurality of types of recording power correction terms Pcn for the disc stored in the optical recording / reproducing apparatus in advance. (N is an integer, for example, n = 1, 2, 3... 16), or a recording power correction term Pcn recorded in advance in the information control area of the optical disc is reproduced and read, and a plurality of types of recording power correction terms are read. Pcn may be set. Even when set in this way, the same effect as in the first embodiment can be obtained.

  In the first embodiment, the setting of the plurality of types of recording power correction terms Pcn in (S103) is not limited to the above method, and the plurality of types of recording power correction terms Pcn for the disc stored in the optical recording / reproducing apparatus in advance. Is read out, or a range in which a plurality of types of recording power correction terms Pcn stored in advance in the control information area of the optical disc is reproduced and read out, and the optical recording / reproducing apparatus arbitrarily selects a plurality of types within the range. The recording power correction term Pcn may be set. Even when set in this way, the same effect as in the first embodiment can be obtained.

  In the first embodiment, the calculation of the optimum recording power Popt in (S106) is not limited to the above method, and the optimum recording power Popt and recording of the relevant disc in the conventional κ method, which are recorded in advance in the control information area of the optical disc. The ratio Popt / Pth = κxρ of the power threshold value Pth is read, the correction value α ′ stored in the optical recording / reproducing apparatus in advance is read, and the expression Popt = α′x (κxρ) × Pth is calculated using κxρ and α ′. To calculate the optimum recording power Popt. Even when set in this way, the same effect as in the first embodiment can be obtained.

  In addition, the said embodiment is a part of Example of this invention, Comprising: It is not restricted to the said Example. When the main part of the present invention is employed, the same effect may be obtained even if there is a difference in details.

FIG. 7 is a diagram showing an example of a relationship characteristic between a recording power Pw and an evaluation value MxPw in an optical disc in which accurate recording power adjustment cannot be performed by the conventional κ method, and at the same time, an optimum using the recording power threshold Pth and the Pth using the conventional κ method. The result of having performed recording power Popt determination is shown. Linear approximation ranges 1 and 2 in the figure indicate the measurement point ranges used when determining the recording power threshold Pth in the cases 1 and 2. In the optical disk having the relational characteristics shown in FIG. 1, the variation of the recording power threshold Pth determined when the recording power adjustment is performed 100 times using the conventional κ method is shown by the change amount and the frequency with respect to the average value of Pth. FIG. It is a figure which shows typically the fluctuation | variation of the modulation degree accompanying a Henv fluctuation | variation. FIG. 4 is a diagram illustrating an example of a relational characteristic between the recording power Pw and the modulation degree M in the states (a) and (b) when the modulation degree fluctuation of FIG. 3 occurs in the optical disk having the relational characteristic of FIG. The target recording power Ptarget determined in each of the states a) and (b) is shown. FIG. 4 is a diagram illustrating an example of the relational characteristic between the recording power Pw and the evaluation value MxPw in the states (a) and (b) when the modulation degree fluctuation of FIG. 3 occurs in the optical disc having the relational characteristic of FIG. The recording power threshold Pth and the optimum recording power Popt determined using the conventional κ method in the states of (a) and (b) are shown. This is determined when the recording power is adjusted 100 times using the conventional κ method in the states (a) and (b) when the modulation degree fluctuation of FIG. 3 occurs in the optical disk having the relational characteristics of FIG. FIG. 6 is a diagram illustrating an example of a variation in recording power threshold value Pth and its frequency. FIG. 1 shows an example of the variation of the recording power threshold value Pth determined when the recording power is adjusted 100 times using the present invention in the optical disk having the relational characteristics shown in FIG. FIG. Recording on the optical disk having the relational characteristics shown in FIG. 1 is determined when the recording power is adjusted 100 times using the present invention in the states (a) and (b) in the case where the modulation degree fluctuation shown in FIG. 3 occurs. It is a figure of an example which shows the dispersion | variation in the power threshold value Pth, and its frequency. 1 is a block diagram illustrating an example of a main part configuration of an optical disc apparatus according to an embodiment of the present invention. It is an example block diagram which shows the control part of the optical disk apparatus in the Example of this invention. 3 is a flowchart of a recording power determination method of the present invention. FIG. 6 is an example of a relational characteristic between a recording power Pw and a modulation degree M. It is an example showing that the relational characteristic between the corrected recording power (Pw−Pcn) and the modulation degree Mx (Pw−Pcn) changes with the change of the recording power correction term Pcn. FIG. 10 is a diagram illustrating an example of a result obtained by linearly approximating a relational characteristic between a corrected recording power (Pw−Pc0) and a modulation degree Mx (Pw−Pc0), and a method of calculating a corrected recording power Pth0 and a recording power threshold Pth determined simultaneously. Indicates.

Explanation of symbols

10: optical disk, 12: spindle motor, 14: optical pickup unit, 16: laser beam, 18: encoder, 20: LD drive unit, 22: control unit, 24: RF signal processing unit, 26: decoder, 28: Henv, Lenv acquisition unit.

Claims (15)

In a recording power adjustment method for recording information on an information recording medium by irradiating light and / or reproducing information from the information recording medium,
A method of trial writing a signal with a plurality of types of recording power on an information recording medium, and adjusting the recording power based on the reproduction signal quality of the signal,
Obtaining a modulation degree Mm from a reproduction signal amplitude of a signal written by trial using a plurality of types of recording power Pwm;
Setting a recording power correction term Pcn;
Obtaining an evaluation value Smn = Mmx (Pwm−Pcn) from the corrected recording power (Pwm−Pcn) obtained from the recording power correction term Pcn and the recording power Pwm and the modulation degree Mm;
Obtaining an optimum recording power correction term Pc0 based on a relational characteristic between the corrected recording power (Pwm−Pcn) and the evaluation value Smn;
Obtaining a corrected recording power Pth0 at which the evaluation value Sm0 becomes zero when a relational characteristic between the correction recording power (Pwm−Pc0) and the evaluation value Sm0 in the optimum recording power correction term Pc0 is linearly approximated;
Obtaining a recording power threshold value Pth using the corrected recording power Pth0 and the optimum recording power correction term Pc0;
Obtaining an optimum recording power Popt based on the recording power threshold value Pth;
A recording power adjustment method comprising: In the step of obtaining the optimum recording power correction term Pc0,
Comparing a relational characteristic between the corrected recording power (Pwm-Pcn) and the evaluation value Smn;
Determining the recording power correction term Pcn as the optimum recording correction term Pc0 when the relational characteristic is closest to a straight line;
2. The recording power adjustment method according to claim 1, further comprising: In the step of obtaining the optimum recording power Popt,
The step of calculating the optimum recording power Popt using the recording power threshold Pth and the ratio α between the optimum recording power Popt and the recording power threshold Pth set for each information recording medium is provided. The recording power adjustment method according to claim 1.   4. The recording power adjustment method according to claim 3, wherein the ratio α between the optimum recording power Popt and the recording power threshold value Pth is obtained from control information recorded on an information recording medium. In a recording power adjustment method for recording information on an information recording medium by irradiating light and / or reproducing information from the information recording medium,
A method of trial writing a signal with a plurality of types of recording power on an information recording medium, and adjusting the recording power based on the reproduction signal quality of the signal,
The optimum recording power correction term Pc0 is obtained using the evaluation value Smn obtained from the recording power Pwm, the recording power correction term Pcn, and the modulation degree Mm.
The recording power threshold value Pth is obtained from the relationship with the corrected recording power Pth0 at that time,
A recording power adjustment method, wherein the optimum recording power Popt is obtained by using a ratio α between an optimum recording power Popt recorded on an information recording medium and a recording power threshold value Pth. When obtaining the optimum recording power correction term Pc0,
By comparing the relational characteristics between the corrected recording power (Pwm-Pcn) represented by the difference between the recording power Pwm and the recording power correction term Pcn and the evaluation value Smn, the recording when the recording line is closest to the straight line is obtained. 6. The recording power adjustment method according to claim 5, wherein an optimum recording correction term Pc0 is obtained from the power correction term Pcn.   The ratio α between the optimum recording power Popt and the recording power threshold value Pth is set for each information recording medium, and the ratio α is recorded in advance on the information recording medium. 5. The recording power adjustment method according to 5. 6. The recording power adjustment method according to claim 5, wherein the ratio α between the optimum recording power Popt and the recording power threshold value Pth is used as a predetermined value regardless of the information recording medium. In an optical recording / reproducing apparatus for recording information on an information recording medium by irradiating light and / or reproducing information from the information recording medium,
Means for adjusting recording power when recording information on at least the information recording medium;
The recording power adjusting means is
Means for obtaining a modulation degree Mm from a reproduction signal amplitude of a signal written by trial using a plurality of types of recording power Pwm;
Means for setting a recording power correction term Pcn;
Means for obtaining an evaluation value Smn = Mmx (Pwm−Pcn) from the corrected recording power (Pwm−Pcn) obtained from the recording power correction term Pcn and the recording power Pwm and the modulation degree Mm;
Means for obtaining an optimum recording power correction term Pc0 based on a relational characteristic between the corrected recording power (Pwm-Pcn) and the evaluation value Smn;
Means for obtaining a corrected recording power Pth0 at which the evaluation value Sm0 becomes zero when a relational characteristic between the correction recording power (Pwm-Pc0) and the evaluation value Sm0 in the optimum recording power correction term Pc0 is linearly approximated;
Means for obtaining a recording power threshold value Pth using the corrected recording power Pth0 and the optimum recording power correction term Pc0;
Means for obtaining an optimum recording power Popt based on the recording power threshold value Pth;
An optical recording / reproducing apparatus comprising: The means for obtaining the optimum recording power correction term Pc0 further comprises:
Means for comparing a relational characteristic between the corrected recording power (Pwm-Pcn) and the evaluation value Smn;
Means for determining, as the optimum recording correction term Pc0, the recording power correction term Pcn when the relational characteristic is closest to a straight line;
The optical recording / reproducing apparatus according to claim 9, comprising: The means for obtaining the optimum recording power Popt further comprises:
10. The optical recording / reproducing apparatus according to claim 9, further comprising means for determining a ratio α between the recording power threshold Pth and the optimum recording power Popt set for each information recording medium and the recording power threshold Pth. . Means for obtaining the optimum recording power Popt;
12. The optical recording / reproducing apparatus according to claim 11, wherein the optimum recording power Popt is obtained from αxPth using the ratio α obtained by the means for determining the ratio α.   13. The optical recording / reproducing apparatus according to claim 12, wherein the ratio α between the optimum recording power Popt and the recording power threshold value Pth is determined by acquiring control information recorded on an information recording medium. The means for determining the ratio α is:
12. The optical recording / reproducing apparatus according to claim 11, wherein said optical recording / reproducing apparatus is a means for selecting and determining a desired ratio α from a plurality of ratios α corresponding to each of a plurality of information recording media.   The optical recording / reproducing apparatus according to claim 14, wherein the plurality of ratios α are set in advance.

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